Tuesday March 26, 2019
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Dangers Of Mining Waste In Brazil

"We have the technology and we have the expertise, and the mining industry frankly has fought making those changes,"

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Brazil, Mining
An Indigenous man from the Pataxo Ha-ha-hae tribe looks at Paraopeba river, after a tailings dam owned by Brazilian mining company Vale SA collapsed, in Sao Joaquim de Bicas near Brumadinho, Brazil, Jan. 25, 2019. VOA

As rescuers in Brazil search for survivors of a dam collapse, questions abound about the health and environmental risks of the thick, brown, metal-laden mine waste that flowed over buildings. The accident comes after the United Nations and others warned that dam failures in the mining industry are becoming increasingly catastrophic because the structures are growing larger and more numerous around the globe.

A look at some of the hazards:

What Are Mine Tailings and How Are They Stored?

Mine tailings are large volumes of waste rock and other material left behind after companies dig up mineral-bearing ore and run it through mechanical and chemical processes to remove the most valuable components. The tailings are disposed of in ponds or other “impoundments,” often in a mud-like mixture of water and rock known as slurry.

A single large mine can produce hundreds of thousands of tons of tailings each day that are typically pumped into a massive holding area behind a dam, where the waste can remain for decades. Tailings piles can be dry enough on the surface to allow people to walk on them, but the inside is often wet, with a jelly-like consistency. A breach can release a runny, muddy material.

Mining
This is one of of the gold mines around Cobar. Flickr

In Friday’s disaster in Brumadinho, Brazil, the dam that failed was 282 feet (86 meters) high and held more than 400 million cubic feet (11.7 million cubic meters) of waste material, according to its owner, Brazilian-mining company Vale.

Are the Tailings Toxic?

The composition of tailings varies from mine to mine, with some containing radioactive material, heavy metals and even cyanide, which is used in silver and gold extraction.

Vale representatives have insisted that the slow-moving mud spreading down the Paraopeba River following Friday’s collapse is composed mostly of silica, or sand, and is non-toxic. But environmental groups contend the iron ore mine waste contains high levels of iron oxide that could cause irreversible damage.

A similar disaster in 2015 at a Vale-operated mine in the same region of Brazil killed 19 people and released 78 million cubic feet (60 million cubic meters) of mud that polluted hundreds of miles of rivers and streams. In that case, a U.N. report found that the waste “contained high levels of toxic heavy metals.”

Beyond the chemical dangers, a huge rush of muddy water into a river system can have long-lasting environmental effects, plastering the riverbed with silt that kills fish and vegetation.

Mining
Mine Waste. Flickr

The 2015 accident in Samarco, Brazil, left 250,000 people without drinking water after downstream supply systems were tainted or otherwise disrupted by mud.

Another danger from a tailings dam breach is that the sudden release can overtop a river’s normal channel and deposit contaminants on normally dry land, said Ellen Wohl, a geology professor at Colorado State University.

Those contaminants can later wash back into the river, re-polluting the water, she said. The contaminants can also become airborne if floodwaters deposit them on the riverbank, where they can dry out and blow away, said Marco Kaltofen, who is also a nuclear and chemical engineering researcher at Worcester Polytechnic Institute.

How Often Do the Dams Fail and What Happens When They Do?

These types of dam failures are increasingly devastating because mines operate on a much larger scale than in the past, producing more tailings that require bigger dams.

There are an estimated 18,000 tailings dams worldwide, according to David Chambers with the Center for Science in Public Participation, which consults with government agencies and private groups on mining pollution issues.

A 2017 U.N report identified 40 significant dam failures over the prior decade — including in Canada, China, Brazil and Chile. A compilation of dam failures by Chambers and others tallied 435 people killed over the same time period.

Mining
Acid rock drainage occurs naturally within some environments as part of the rock weathering process but is exacerbated by large-scale earth disturbances characteristic of mining Flickr

“We can’t tell you where a failure is going to occur, but statistically we can tell you they are going to happen,” Chambers said.

What is Being Done to Prevent Tailings Dam Failures?

The dams can be threatened by earthquakes, undiscovered geologic faults and heavy rainstorms, and each of those threats has many unknowns, said Dermot Ross-Brown, a longtime mining consultant and a part-time professor at the Colorado School of Mines.

Mining companies use the best science and consultants they can find, he said. “It’s just that the problem is so big, and they have imperfect knowledge of what the geology is.”‘

Last year’s report from the U.N. recommended that governments and mining companies adopt a “zero-failure” goal for mining impoundments.

In 2016, in the wake of the Samarco spill, the International Council on Mining and Metals said instances of catastrophic mine waste impoundment failures were unacceptable. The organization issued new safety guidelines, and called on companies to use construction methods and operating practices that minimize the chances of accidents.

Also Read: Brazil’s New President Claims Indigenous Lands

But the industry’s critics say such calls for reforms have yielded few changes and more dam failures are inevitable without stepped-up construction practices and inspection regimes. They say more also needs to be done to make sure that people are not living or working just downstream of the dams, where they are at the greatest risk in a failure.

“We have the technology and we have the expertise, and the mining industry frankly has fought making those changes,” said Payal Sampat with the U.S.-based environmental group Earthworks. (VOA)

Next Story

U.S. President Donald Trump Suggests, Brazil Should be Able To Join The North Atlantic Treaty Alliance

Until now, Brazilian diplomacy was a zero-sum kind of relationship, not aligned with U.S. interests and "sort of hostile in certain ways, at least at the bureaucratic level"

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U.S.
President Donald Trump greets Brazilian President Jair Bolsonaro during a news conference in the Rose Garden of the White House, March 19, 2019. VOA

The leaders of the Western Hemisphere’s two largest economies are pledging closer trade ties and enhanced military cooperation, with U.S. President Donald Trump even suggesting Brazil should be able to join the North Atlantic Treaty Alliance (NATO).

Trump said for that to happen, however, he would “have to talk to a lot of people.”

The U.S. president, at a joint news conference with Brazilian President Jair Bolsonaro, also pledged American support for Brazil to join the 36-member Organization for Cooperation and Economic Development (OECD), which includes most of the highly-developed economies.

Bolsonaro, speaking in Portuguese, said his visit begins a new chapter of cooperation between Brazil and the United States, adding that with his recent election, “Brazil has a president who is not anti-American, which is unprecedented in recent decades.”

U.S.
“All options are open,” Trump reiterated when asked by a reporter in the White House Rose Garden if military intervention in Venezuela by the United States is possible. VOA

The retired military officer is known as the “Trump of the Tropics” for his far-right agenda of cracking down on crime and corruption, and nostalgia for Brazil’s era of military dictatorship.

The two leaders, who met for the first time Tuesday, also discussed their mutual support for Venezuelan opposition leader Juan Guaido, who has been recognized as Venezuela’s legitimate leader by most Western countries, including the United States and Brazil.

“All options are open,” Trump reiterated when asked by a reporter in the White House Rose Garden if military intervention in Venezuela by the United States is possible.

Trump noted that Washington has yet to apply really tough sanctions on Caracas, where Nicolas Maduro — who the U.S. president called “Cuba’s puppet” — remains in power with the backing of Venezuela’s military.

In oil-rich Venezuela there is no food, water or air-conditioning, according to Trump, while Bolsonaro said “people are starving to death” there.

“We need to put an end to this,” Bolsonaro added.

Space launches

Just ahead of the meeting between the two leaders, the United States and Brazil signed an agreement to support American space launches from Brazil. The State Department says the pact will ensure the proper handling of sensitive U.S. technology consistent with U.S. nonproliferation policy, the Missile Technology Control, and U.S. export control laws and regulations.

The two leaders “agreed to take the steps necessary to enable Brazil to participate in the Department of Homeland Security’s Trusted Traveler Global Entry Program,” according to a joint statement issued following the news conference.

President Donald Trump speaks during a meeting with Brazilian President Jair Bolsonaro in the Oval Office of the White House, March 19, 2019, in Washington.
President Donald Trump speaks during a meeting with Brazilian President Jair Bolsonaro in the Oval Office of the White House, March 19, 2019, in Washington. VOA

‘Common ground’

The two countries have never had particularly close relations, with Brazil traditionally wary of American influence in Latin America. But now their two leaders find themselves in sync on concerns about the Maduro regime in Venezuela, Cuba’s involvement in that country, and the threat from China’s rising influence on domestic politics in South and Central America.

Also Read: Here’s Why Some Young Adults Engage in Unsafe Sex

Until now, Brazilian diplomacy was a zero-sum kind of relationship, not aligned with U.S. interests and “sort of hostile in certain ways, at least at the bureaucratic level,” former Assistant Secretary of State for Western Hemisphere Affairs Roger Noriega told VOA.

“If we can find common ground with them on some key specific initiatives,” the U.S. relationship with Brazil and South America, as a whole, can be realigned, according to Noriega, an American Enterprise Institute visiting fellow.(VOA)